Open AccessThe mass and temperature functions in a moving‐barrier model
Author(s) -
Del Popolo A.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05932.x
Subject(s) - physics , excursion , halo , function (biology) , halo mass function , extension (predicate logic) , statistical physics , astrophysics , evolutionary biology , galaxy , political science , computer science , law , biology , programming language
In this paper, I use the extension of the excursion set model of Sheth & Tormen and the barrier shape obtained in Del Popolo & Gambera to calculate the unconditional halo mass function, and the conditional mass function in several cosmological models. I show that the barrier obtained in Del Popolo & Gambera, which takes account of tidal interaction between protohaloes, is a better description of the mass functions than the spherical collapse and is in good agreement with numerical simulations. The results are also in good agreement with those obtained by Sheth & Tormen – only slight differences are observed especially at the low‐mass end. Moreover I calculate, and compare with simulations, the temperature function obtained by means of the mass functions calculated previously and also using an improved version of the M – T relation, which accounts for the fact that massive clusters accrete matter quasi‐continuously, and finally taking account of the tidal interaction with neighbouring clusters. Even in this case the discrepancy between the Press–Schechter predictions and simulations is considerably reduced.